TWI631828B - Frequency-generating circuit and communications apparatus - Google Patents

Abstract

The invention provides a frequency generating circuit and a communication device. The frequency generating circuit includes a frequency synthesizer circuit and a reference clock signal processor. The frequency synthesizer circuit receives the processed reference clock signal and generates a radio frequency clock signal according to the processed reference clock signal. The reference clock signal processor receives the initial reference clock signal from the oscillator, and processes the initial reference clock signal according to the instruction signal to generate a processed reference clock signal. The indication signal is generated based on the required reference clock frequency of the communication device. When the required reference clock frequency is higher than the first threshold, the frequency of the processed reference clock signal is a multiple of the initial reference clock signal frequency; when the required reference clock frequency is lower than the second threshold, the initial reference clock signal The frequency is a multiple of the reference clock signal frequency after processing.

Description

Frequency generating circuit and communication equipment

The present invention relates to mobile communications, and more particularly to a frequency-generating circuit and a related control method.

With the emergence of various technologies behind cellular networks, embedded systems, and the Internet, mobile communication devices (devices) such as smartphones and tablets combine the mobility of a cellular phone with a computer or personal digital assistant (Personal Digital Assistant, The functionality of PDAs) has been combined into a single device and is therefore becoming increasingly popular.

Since the power supply of mobile communication devices is often limited by batteries, how to reduce power consumption and extend the standby and operating time of mobile communication devices has become a problem worthy of attention.

Therefore, it is necessary to propose a novel frequency generation circuit architecture and related control methods.

The invention provides a frequency generating circuit, including: a frequency synthesizer circuit, receiving a processed reference clock signal, and generating a radio frequency clock signal according to the processed reference clock signal; and a reference clock signal processor Receiving an initial reference clock signal from an oscillator, and processing the initial reference clock signal according to an instruction signal to generate the processed reference clock signal No., wherein the indication signal is generated according to a required reference clock frequency of a communication device, and when the required reference clock frequency is higher than a first threshold, one of the processed reference clock signals is The frequency is a multiple of a frequency of the initial reference clock signal; when the required reference clock frequency is lower than a second threshold, the frequency of the initial reference clock signal is the post-processing reference A multiple of said frequency of the pulse signal.

In another embodiment of the present invention, a communication device is provided, which includes: a frequency generating circuit that generates a radio frequency clock signal based on an initial reference clock signal; and a reference clock controller based on a required reference clock An indication signal is generated at a frequency, wherein the frequency generation circuit includes: a frequency synthesizer circuit that receives a processed reference clock signal and generates the radio frequency clock signal according to the processed reference clock signal; and The reference clock signal processor receives the initial reference clock signal from an oscillator, and processes the initial reference clock signal according to the instruction signal to generate the processed reference clock signal, wherein when the When the required reference clock frequency is higher than a first threshold, a frequency of the processed reference clock signal is a multiple of a frequency of the initial reference clock signal; when the required reference clock frequency is lower than At a second threshold, the frequency of the initial reference clock signal is a multiple of the frequency of the processed reference clock signal.

100‧‧‧communication equipment

110‧‧‧Radio Transceiver

120‧‧‧ modem

130‧‧‧Application Processor

140‧‧‧User Identification Card

150‧‧‧Memory

221‧‧‧ fundamental frequency processing device

222‧‧‧Processor

223‧‧‧ Internal Memory

224‧‧‧ network card

300‧‧‧frequency generating circuit

310‧‧‧Frequency Synthesizer Circuit

320‧‧‧ Reference Clock Signal Processor

330‧‧‧Reference Clock Controller

340‧‧‧Oscillator

350‧‧‧LO generator

360‧‧‧Mixer

FIG. 1 is an exemplary block diagram of a communication device according to an embodiment of the present invention.

FIG. 2 is an exemplary block diagram of a modem according to an embodiment of the present invention; Illustration.

FIG. 3 is an exemplary block diagram of a frequency generating circuit according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of an exemplary scenario of dynamically adjusting a reference clock signal frequency according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of an exemplary scenario of dynamically adjusting a reference clock signal frequency according to another embodiment of the present invention.

FIG. 6 is a system schematic diagram of one of the multiple conversion methods for processing an initial reference clock signal according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of a simulation result of dynamically adjusting a reference clock signal frequency according to an embodiment of the present invention.

This section describes the best way to implement the present invention. The purpose is to explain the spirit of the present invention and not to limit the scope of protection of the present invention. The scope of the present invention is defined by the scope of patent application.

Certain terms are used in this patent specification and the scope of patent applications to refer to specific elements. It should be understood by those with ordinary knowledge in the art that hardware manufacturers may use different names to refer to the same component. The scope of this patent specification and application for patent does not take the difference in names as a way to distinguish components, but rather uses the difference in functions of components as a criterion for distinguishing components. "Inclusion" or "including" mentioned in the entire specification and the scope of patent application is an open-ended term, so it should be interpreted as "including but not limited to"; "component", "system" and "equipment" A computer-related entity, which can be hardware, software, or a combination of hardware and software. In addition, the term "coupled" includes any direct And indirect electrical connection means. Therefore, if a first device is described as being coupled to a second device, it means that the first device can be electrically connected directly to the second device or indirectly electrically connected to the second device through other devices or connection means.

FIG. 1 is an exemplary block diagram of a communication device according to an embodiment of the present invention. The communication device 100 may be a portable electronic device, such as a mobile station (Mobile Station, MS). The MS may be referred to as User Equipment (UE). The communication device 100 may include at least one antenna module, a radio transceiver 110, a modem 120, an application processor 130, a user identity card 140, and a memory 150. The antenna module includes at least one antenna. The radio transceiver 110 may receive radio frequency (RF) signals through an antenna module, send wireless RF signals through the antenna module, and perform RF signal processing. For example, the radio transceiver 110 may convert the received signal into an intermediate frequency or a base frequency signal for processing. Alternatively, the radio transceiver 110 may receive an IF or baseband signal from the data transmitter 120 and convert the received signal into a wireless RF signal for transmission to a network device. According to an embodiment of the present invention, the network device may be a network cell, an evolved node B, a base station, a Mobility Management Entity (MME), etc. The RF signal is in communication with the communication device 100.

The radio transceiver 110 may include multiple hardware devices for radio frequency conversion and RF signal processing. For example, the radio transceiver 110 may be a circuit and may include a power amplifier circuit To amplify the RF signal; a filter circuit to filter out unnecessary parts of the RF signal; a frequency generating circuit to generate a signal oscillating at a desired radio frequency; and / or a mixer circuit to perform radio frequency conversion. According to an embodiment of the present invention, the radio frequency may be 900 MHz or 1800 MHz for Global System for Mobile communications (GSM), or 1900 MHz for Universal Mobile Telecommunications System (UMTS), or Any specific frequency band used in a Long-Term Evolution (LTE) system.

The modem 120 may be a cellular communication modem to process the operation of the cellular system communication protocol, and to process IF or baseband signals received from the radio transceiver 110 or to be transmitted to the radio transceiver 110. The application processor 130 is used to run an operating system of an application architecture of the communication device 100 and to run application programs installed in the communication device 100. In the embodiment of the present invention, the data machine 120 and the application processor 130 may be designed as independent chips, which are coupled to each other through some buses or hardware interfaces; or the data machine 120 and the application processor 130 may be integrated into In a combo chip (ie, System on Chip (SoC)). Of course, the invention is not limited to this.

The user identification card 140 may be a SIM, USIM, R-UIM, or CSIM card, and generally includes user account information, an International Mobile Subscriber Identity (IMSI), and a series of SIM Application Toolboxes (SIM Application Toolkit (SAT) command, and provides storage space for phonebook contacts. The memory 150 may be coupled to the modem 120 and the application processor 130, and may store system data or user data.

Please note that in order to clarify the concept of the present invention, FIG. 1 only shows A simplified block diagram of elements related to the present invention is provided. For example, in some embodiments of the present invention, the communication device 100 may further include some peripheral devices not shown in FIG. 1. In other embodiments of the present invention, the communication device 100 may further include a central controller coupled to the modem 120 and the application processor 130. Therefore, the present invention is not limited to the content shown in FIG.

Please also note that although Figure 1 shows a single card single standby application, the present invention is not limited to this. For example, in some embodiments of the present invention, the communication device may include multiple user identification cards to support multiple radio access technology (RAT) communications. In multi-RAT communication applications, modems, radio transceivers, and / or antenna modules can be shared by user identification cards, and can have the operation of processing multiple cellular system communication protocols and in accordance with multiple cellular system communication protocols. The ability to process the corresponding RF, IF or fundamental frequency signals. Those with ordinary knowledge in the art can make changes and modifications based on the above description to obtain a communication device including multiple radio transceivers and / or multiple antenna modules to support multi-RAT wireless communication, which should all be covered by the present invention. The scope is in accordance with the spirit of the present invention. Therefore, in some embodiments of the present invention, by making some changes and modifications, the communication device can be designed to support multi-card multi-standby applications.

Please note that the user identification card 140 may be the above-mentioned dedicated hardware card. Or, in some embodiments of the present invention, the identification code, number, address, etc. of the corresponding communication device can be burned into the internal memory of the corresponding data machine. Therefore, the present invention is not limited to what is shown in the drawings.

FIG. 2 is an exemplary view of a modem according to an embodiment of the present invention Block diagram. The modem 120 may include at least one baseband processing device 221, a processor 222, an internal memory 223, and a network card 224. The baseband processing device 221 may receive an IF or baseband signal from the radio transceiver 110 and may perform IF or baseband signal processing. For example, the baseband processing device 221 may convert an IF or baseband signal into a plurality of digital signals, and process the digital signals, and vice versa. The baseband processing device 221 may be a circuit and may include multiple circuits for performing signal processing, such as an analog-to-digital converter circuit for performing analog-to-digital conversion, and digital-to-analog conversion for performing digital-to-analog conversion Circuit, amplifier circuit for performing gain adjustment, modulator for performing signal modulation, demodulator for performing signal demodulation, encoder for performing signal encoding, and decoding for signal Decoder, etc.

The processor 222 can control the operation of the modem 120. According to an embodiment of the present invention, the processor 222 may execute code in a corresponding software module of the modem 120. The processor 222 may maintain and execute various tasks, threads, and / or protocol stacks for different software modules. In a preferred embodiment, the communication protocol stack can be used to handle the radio activity of a RAT. However, multiple communication protocol stacks can also be used to simultaneously process radio activities of one RAT, or only one communication protocol stack can be used to simultaneously process radio activities of multiple RATs, and the present invention is not limited thereto.

The processor 222 may also read data from a user identification card (such as the user identification card 140) coupled to the modem 120, and may write data into the user identification card. The internal memory 223 can store system data and user data for the modem 120. The processor 220 may also access the internal memory 223.

The network card 224 can provide Internet access services for communication devices. Please note that although the network card 224 shown in FIG. 2 is disposed in the modem, the present invention is not limited to this. In some embodiments of the present invention, the communication device may also include a network card configured outside the modem, or the communication device may be coupled to an external network card for providing Internet access services. Therefore, the present invention is not limited to any one embodiment.

In addition, please note that, in order to clarify the concept of the present invention, FIG. 2 shows a simplified block diagram in which only components related to the present invention are shown. Therefore, the present invention is not limited to the content shown in FIG. 2.

In addition, please note that in some embodiments of the present invention, the data machine may include more than one processor and / or more than one baseband processing device. For example, the modem may include multiple processors and / or multiple baseband processing devices to support multi-RAT operation. Therefore, the present invention is not limited to the content shown in FIG. 2.

FIG. 3 is an exemplary block diagram of a frequency generating circuit according to an embodiment of the present invention. The frequency generating circuit 300 generates a radio frequency clock signal CK_RF according to an original reference clock signal CK_Ref. According to an embodiment of the present invention, the frequency generating circuit 300 may include at least a frequency synthesizer circuit 310 and a reference clock signal processor 320.

The reference clock signal processor 320 receives the initial reference clock signal CK_Ref from an oscillator 340, processes the initial reference clock signal CK_Ref according to the instruction signal S_Ind, and generates a processed reference clock signal CK_ProcRef. The indication signal S_Ind may be generated according to a required reference clock frequency of the communication device.

The frequency synthesizer circuit 310 receives the processed reference clock signal CK_ProcRef, and performs operation on the processed reference clock signal CK_ProcRef to generate a radio frequency clock signal CK_RF according to the processed reference clock signal CK_ProcRef. According to an embodiment of the present invention, the frequency synthesizer circuit 310 may be an All-Digital Phase Locked Loop (ADPLL), an analog PLL, or any other type of PLL. The ADPLL may be a Multi Modulus Divider-less (MMD-less) ADPLL or an MMD ADPLL.

The radio frequency clock signal CK_RF may be provided to a local oscillation signal generator (referred to as an LO generator for short) 350. The LO generator 350 may further process the radio frequency clock signal CK_RF (such as dividing the frenquency of the radio frequency clock signal CK_RF), and generate a processed radio frequency clock signal CK'_RF. The mixer 360 can receive the processed radio frequency clock signal CK'_RF and multiply the processed radio frequency clock signal CK'_RF by the data signal Data to carry the data signal Data on a carrier frequency. Please note that in some embodiments, the mixer 360 can also directly receive the unprocessed radio frequency clock signal CK_RF and multiply the radio frequency clock signal CK_RF by the data signal Data. The present invention is not limited thereto.

According to an embodiment of the present invention, the frequency generating circuit 300 may further include a reference clock controller 330. Of course, according to different embodiments, the reference clock controller 330 may be located in the communication device where the frequency generating circuit 300 is located and not in the frequency generating circuit 300. The reference clock controller 330 generates an instruction signal S_Ind and a control signal S_Ctrl according to a required reference clock frequency. The reference clock signal processor 320 may determine the frequency of the reference clock signal CK_ProcRef after processing according to the indication signal S_Ind. Because of the reference clock signal after processing The frequency of CK_ProcRef can be adjusted dynamically, and the frequency synthesizer circuit 310 can also control or adjust the parameters used to generate the RF clock signal CK_RF according to the control signal S_Ctrl (or according to the required reference clock frequency). For example, the parameter may be a divisor of a frequency divider included in the frequency synthesizer circuit 310, a bandwidth of a filter included in the frequency synthesizer circuit 310, and the like. In an embodiment of the present invention, the divisor refers to the ratio of the frequency of the radio frequency clock signal CK_RF to the frequency of the processed reference clock signal CK_ProcRef.

Please note that in the embodiment of the present invention, the reference clock controller 330 may be implemented by a dedicated hardware circuit or a software module. When the reference clock controller 330 is implemented by a software module, the processor 222 of the modem 120 can run the code in the software module to implement the corresponding function.

The oscillator 340 may be a crystal oscillator for generating an initial reference clock signal CK_Ref as a fundamental clock signal having an accurate frequency. The initial reference clock signal CK_Ref can be provided not only to the frequency generating circuit 300 but also to any other circuit component in the communication device 100 that requires a basic clock signal. Generally, an oscillator is used to generate a basic clock signal with a predefined frequency. When multiple basic clock signals with different frequencies are required, multiple oscillators should be used.

However, as the number of oscillators increases, the circuit area and hardware cost also increase. In order to reduce the power consumption of the communication device 100 without increasing the number of oscillators, a novel frequency generation circuit architecture and control method are specifically proposed.

According to an embodiment of the present invention, reference is made to the clock signal processor 320 The frequency of the reference clock signal can be dynamically adjusted according to different reference clock frequency requirements of the communication device 100 to reduce the power consumption of the communication device 100.

For the frequency synthesizer circuit 310 that uses the processed reference clock signal CK_ProcRef as a reference to generate the radio frequency clock signal CK_RF, when the frequency of the processed reference clock signal CK_ProcRef is high, the control frequency of the frequency synthesizer circuit 310 is high. The width can be wide, so the noise (such as integrated phase error) generated in the RF clock signal CK_RF is smaller, and the settling time is shorter. The clock frequency stabilization time is defined as an unlocked state to a locked state, that is, the time required for the frequency synthesizer circuit 310 to lock the frequency of the radio frequency clock signal CK_RF to a target frequency. Generally, when the frequency of the RF clock signal CK_RF is locked, the phase error can be less than a predefined value, such as 1 ppm or 5 degrees.

On the other hand, when the frequency of the reference clock signal CK_ProcRef after processing is low, although compared to when the frequency of the reference clock signal CK_ProcRef after processing is high, noise may be larger and the clock frequency stabilization time may be It will be longer, but the power consumption of the frequency synthesizer circuit 310 may be lower.

Therefore, in the embodiment of the present invention, the reference clock signal processor 320 may dynamically adjust the frequency of the reference clock signal according to different reference clock frequency requirements of the communication device 100 to reduce the power consumption of the communication device 100.

According to an embodiment of the present invention, the reference clock controller 330 may determine a reference clock frequency requirement of the communication device 100 according to a plurality of factors, and generate an instruction signal S_Ind and a control signal S_Ctrl according to the required reference clock frequency.

Factors that can be used to determine reference clock frequency requirements can include: Signal-to-noise ratio (SNR) requirements, RF clock frequency stabilization time requirements (i.e., clock frequency stabilization time required by the system required by the communication equipment system), power saving requirements, to be used or being used Modulation order, communication type, data buffer usage, communication status, communication channel type, and stability of the RF clock signal CK_RF.

More specifically, according to an embodiment of the present invention, when the SNR required by the communication device 100 to communicate with the network device is higher than a predefined SNR threshold, the required reference clock frequency is higher; when the required SNR is not Above the predefined SNR threshold, the required reference clock frequency is lower. Generally, the network device can indicate the modulation scheme of the communication. The modulation scheme can be determined according to the condition of the RF channel and the amount of data to be transmitted, and can have corresponding SNR requirements.

According to another embodiment of the present invention, when the required clock frequency stabilization time of the system of the communication device 100 is shorter than a predefined stabilization time threshold, the required reference clock frequency is higher; when the system requires the clock frequency stabilization time and When it is not shorter than the predefined stabilization time threshold, the required reference clock frequency is lower. As described above, the higher the reference clock signal frequency, the shorter the clock frequency stabilization time that the frequency synthesizer circuit 310 can achieve.

According to another embodiment of the present invention, when the communication device 100 does not need to save power, the required reference clock frequency is higher; when the communication device 100 needs to save power, the required reference clock frequency is lower.

According to another embodiment of the present invention, when it is determined that the modulation order to be used or is being used for communication is higher than a predefined modulation order threshold, the required reference clock frequency is higher (because for a higher order modulation , The required SNR is higher). When it is determined that the modulation order to be or is being used for communication is below a predefined modulation order threshold , The required reference clock frequency is lower. For example, 16QAM, 64QAM, and 256QAM are generally regarded as high-order modulation (HOM), while BPSK and QPSK are generally regarded as low-order modulation.

According to another embodiment of the present invention, when a communication type requiring higher SNR or shorter clock frequency stabilization time is to be processed, the required reference clock frequency is higher; when it is to be processed, higher SNR or shorter clock is not required For the communication type of frequency stabilization time, the required reference clock frequency is low. For example, since the data throughput of packet data communication is higher than the data throughput of voice communication, the required reference clock frequency of packet data communication is higher than the required reference clock frequency of voice communication.

According to another embodiment of the present invention, when more data buffers are used, the data throughput is higher and the required reference clock frequency is higher. When the data buffer is used less, the required reference clock frequency is lower. For example, the data buffer used to buffer voice data is relatively less used than the data buffer used to buffer packet data.

According to another embodiment of the present invention, when the communication device 100 is in a state that requires a higher SNR or a shorter clock frequency stabilization time, the required reference clock frequency is higher. When the communication device 100 is in a state that does not require a higher SNR or a shorter clock frequency stabilization time, the required reference clock frequency is lower. For example, when the communication device 100 performs pre-synchronization to synchronize time or frequency with a network device, or operates in a standby mode, a sleep mode, or a discontinuous reception (DRX) off period The communication device 100 may not need a higher SNR or a shorter clock frequency stabilization time. When the communication device 100 performs dedicated data communication (including random access processes, channels Setup, data transfer, etc.) or DRX on period, the communication device 100 may require a higher SNR or a shorter clock frequency stabilization time.

According to another embodiment of the present invention, when the communication device 100 is to communicate with a network device in a data channel for data transmission or reception, the required reference clock frequency is higher. When the communication device 100 is to communicate with the network device on the control channel for control signal transmission or reception, the required reference clock frequency is lower.

According to another embodiment of the present invention, when the radio frequency clock signal CK_RF is not stable (for example, its phase error is higher than a predefined threshold, such as 1 ppm or 5 degrees), the required reference clock frequency is higher (because Fast and stable). When the RF clock signal CK_RF has stabilized, the required reference clock frequency is lower to further reduce power consumption.

Please note that in the embodiments of the present invention, a higher required reference clock frequency may indicate that the required reference clock frequency is higher than a first threshold; a lower required reference clock frequency may indicate a required reference clock frequency. Below a second threshold.

When the required reference clock frequency is high, the reference clock signal processor 320 may perform frequency up-conversion on the received initial reference clock signal CK_Ref to generate a processed reference with a higher frequency. Clock signal CK_ProcRef. Therefore, when the required reference clock frequency is high, the frequency of the processed reference clock signal CK_ProcRef may be higher than the frequency of the initial reference clock signal CK_Ref, and may be a multiple (integer multiple or multiple) of the frequency of the initial reference clock signal CK_Ref. Fractional multiple). Please note that when the required reference clock frequency is high, the reference clock signal processor 320 may also directly output the initial reference clock signal CK_Ref, Without doing any frequency conversion. Therefore, when the required reference clock frequency is high, the frequency of the processed reference clock signal CK_ProcRef may also be equal to the frequency of the initial reference clock signal CK_Ref.

When the required reference clock frequency is low, the reference clock signal processor 320 may perform frequency down-conversion on the received initial reference clock signal CK_Ref to generate a processed reference with a lower frequency. Clock signal CK_ProcRef. Therefore, when the required reference clock frequency is low, the frequency of the processed reference clock signal CK_ProcRef may be lower than the frequency of the initial reference clock signal CK_Ref, and the frequency of the initial reference clock signal CK_Ref may be the processed reference clock signal. Multiples of CK_ProcRef's frequency (integer or fractional). Please note that when the required reference clock frequency is low, the reference clock signal processor 320 may also directly output the initial reference clock signal CK_Ref without any frequency conversion. Therefore, when the required reference clock frequency is low, the frequency of the processed reference clock signal CK_ProcRef may also be equal to the frequency of the initial reference clock signal CK_Ref.

In addition, please note that in the embodiment of the present invention, the frequency of the reference clock signal CK_ProcRef after processing can be dynamically adjusted not only between different radio links, but also established between the network device and the communication device ( The radio link (for communication) is dynamically adjusted during its existence (hitless).

In order to establish a radio link, the network device may give a band number to the communication device 100, and the communication device 100 may perform a honeycomb unit search to find the channel number of the honeycomb unit in the frequency band (such as EUTRA Absolute Radio Channel Number -Frequency Channel Number, EARFCN)), and establish a radio link with the cellular unit. The radio link will be maintained until a hive cell change occurs.

FIG. 4 is a schematic diagram of an exemplary scenario of dynamically adjusting a reference clock signal frequency according to an embodiment of the present invention. Network devices may assign an uplink (UL) -downlink (DL) configuration for communication. Based on different uplink-downlink configurations, downlink-uplink switching can occur in different subframes. However, since the bandwidth required for downlink reception is generally wider than the bandwidth required for uplink transmission, in order to save the power of the transmitter or receiver, the central frequency of the downlink and uplink operations (central frequency )different. Therefore, in order to switch between the downlink and uplink subframes, the center frequency should also be switched.

In order to quickly switch between different center frequencies to meet the requirements of the standard without reducing the communication performance, the clock frequency stabilization time should be as short as possible. Therefore, in this embodiment, when it is determined that it is necessary to switch from a downlink sub-frame to an uplink sub-frame or from an uplink sub-frame to a downlink sub-frame, the reference clock controller 330 may generate an indication signal. S_Ind and control signal S_Ctrl to indicate that the required reference clock frequency is high. As shown in the exemplary scenario in FIG. 4, where the frequency Fref of the initial reference clock signal CK_Ref is 26 MHz, when switching is required, the reference clock signal processor 320 may generate oscillation at a higher frequency (for example, for fast In terms of stable clock frequency, Fref = 52MHz) refers to the clock signal CK_ProcRef after processing. In addition, in response to the control signal S_Ctrl, the frequency synthesizer circuit 310 can adjust parameters used to generate the radio frequency clock signal CK_RF according to the control signal S_Ctrl.

On the other hand, when the reference clock controller 330 determines that it is not necessary to switch When changing or determining that the radio frequency clock signal CK_RF is stable, the reference clock controller 330 may generate an indication signal S_Ind and a control signal S_Ctrl to indicate that the required reference clock frequency is low. In response to the indication signal S_Ind, the reference clock signal processor 320 may generate a processed reference clock signal CK_ProcRef that oscillates at a lower frequency (for example, Fref = 6.5 MHz). In addition, in response to the control signal S_Ctrl, the frequency synthesizer circuit 310 can adjust parameters used to generate the radio frequency clock signal CK_RF according to the control signal S_Ctrl.

FIG. 5 is a schematic diagram of an exemplary scenario of dynamically adjusting a reference clock signal frequency according to another embodiment of the present invention. In this embodiment, the reference clock controller 330 may determine a reference clock frequency requirement according to a communication state and a communication channel type. When the communication device 100 is to communicate with a network device on a data channel for data transmission or reception, a high-order modulation (HOM) is used, and the required reference clock frequency is higher. When the communication device 100 is to perform pre-synchronization or communicate with a network device on a control channel to transmit or receive control signals, the required reference clock frequency is lower.

Therefore, in this embodiment, the reference clock controller 330 may generate an indication signal S_Ind and a control signal S_Ctrl to indicate that the reference clock frequency required for pre-synchronization and control channel communication is low. As shown in the exemplary scenario of FIG. 5, where the frequency Fref of the initial reference clock signal CK_Ref is 26 MHz, in response to the indication signal S_Ind, the reference clock signal processor 320 may generate oscillations at a lower frequency (for example, Fref = 6.5 or 13MHz) after processing the reference clock signal CK_ProcRef. In addition, the frequency synthesizer circuit 310 can also adjust parameters used to generate the radio frequency clock signal CK_RF according to the control signal S_Ctrl.

On the other hand, the reference clock controller 330 may generate an indication signal S_Ind and control signal S_Ctrl to indicate that the reference clock frequency required for data channel communication is high. In response to the indication signal S_Ind, the reference clock signal processor 320 may generate a processed reference clock signal CK_ProcRef that oscillates at a higher frequency (for example, Fref = 52 MHz). In addition, the frequency synthesizer circuit 310 can also adjust parameters used to generate the radio frequency clock signal CK_RF according to the control signal S_Ctrl.

According to an embodiment of the present invention, the reference clock signal processor 320 may selectively output a rising / falling edge of the initial reference clock signal according to the indication signal S_Ind to generate a processed reference clock signal CK_ProcRef.

FIG. 6 is a system schematic diagram of one of the multiple conversion methods for processing an initial reference clock signal according to an embodiment of the present invention. According to an embodiment of the present invention, when the reference clock signal processor 320 up-converts the received initial reference clock signal CK_Ref, the reference clock signal processor 320 may output each rise of the initial reference clock signal CK_Ref Edge and falling edge, and can further invert the falling edge to the rising edge to increase the frequency of the reference clock signal.

As shown in Figure 6, the frequency of the initial reference clock signal Fref = 26MHz. When the required reference clock frequency is high (eg, Fref = 52MHz), the reference clock signal processor 320 may output each rising and falling edge of the initial reference clock signal CK_Ref to make the frequency of the reference clock signal double.

On the other hand, when the reference clock signal processor 320 down-converts the received initial reference clock signal CK_Ref, the reference clock signal processor 320 may not output every rise / Falling edge. The reference clock signal processor 320 may ignore some rising / falling edges of the initial reference clock signal CK_Ref to reduce the frequency of the reference clock signal.

For example, when the frequency of the reference clock signal CK_ProcRef after processing should be 1 / N of the frequency of the initial reference clock signal CK_Ref, the reference clock signal processor 320 may increase every N times the initial reference clock signal CK_Ref / Falling edge outputs a rising / falling edge as the processed reference clock signal CK_ProcRef. Other rising / falling edges of the initial reference clock signal CK_Ref are ignored.

As shown in FIG. 6, when the required reference clock frequency is low, such as Fref = 13MHz, the reference clock signal processor 320 can output a rising / falling signal for every two rising / falling edges of the initial reference clock signal CK_Ref. The falling edge is used as the reference clock signal CK_ProcRef after processing. When the required reference clock frequency is low, such as Fref = 6.5MHz, the reference clock signal processor 320 may output a rising / falling edge for every 4 rising / falling edges of the initial reference clock signal CK_Ref for processing. Post reference clock signal CK_ProcRef.

Please note that since the frequency synthesizer circuit 310 receiving the processed reference clock signal CK_ProcRef is operated by the processed reference clock signal CK_ProcRef (such as by the pulse or edge of the processed reference clock signal CK_ProcRef), When the rising / falling edges become dense or loose, the operating frequency of the frequency synthesizer circuit 310 will increase or decrease accordingly.

According to another embodiment of the present invention, the reference clock signal processor 320 may selectively output a pulse in response to the rising / falling edge of the initial reference clock signal CK_Ref according to the indication signal S-_Ind to generate a processed reference clock signal. No. CK_ProcRef.

In this embodiment, when the reference clock signal processor 320 up-converts the received initial reference clock signal CK_Ref, the reference clock signal processor 320 performs each rise / fall of the initial reference clock signal CK_Ref. Output one or more pulses along the edge to increase the frequency of the reference clock signal.

On the other hand, when the reference clock signal processor 320 down-converts the received initial reference clock signal CK_Ref, the reference clock signal processor 320 may not perform every rising / falling edge of the initial reference clock signal CK_Ref. Output one pulse. The reference clock signal processor 320 may ignore some rising / falling edges of the initial reference clock signal CK_Ref to reduce the frequency of the reference clock signal.

For example, when the frequency of the reference clock signal CK_ProcRef after processing should be 1 / N of the frequency of the initial reference clock signal CK_Ref, the reference clock signal processor 320 may increase every N times the initial reference clock signal CK_Ref A falling pulse is output as a reference clock signal CK_ProcRef after processing. Other rising / falling edges of the initial reference clock signal CK_Ref are ignored.

Since the frequency synthesizer circuit 310 receiving the processed reference clock signal CK_ProcRef is operated by the processed reference clock signal CK_ProcRef (such as by the pulse or edge of the processed reference clock signal CK_ProcRef), when the space between the pulses When becoming dense or loose, the operating frequency of the frequency synthesizer circuit 310 will increase or decrease accordingly.

FIG. 7 is a schematic diagram of a simulation result of dynamically adjusting a reference clock signal frequency according to an embodiment of the present invention. In this embodiment, the reference clock signal The frequency was adjusted from 26MHz to 13MHz at 80μs. As shown in FIG. 7, the phase error indicator (PHI) indicates that the phase error does not increase significantly when the reference clock frequency is adjusted. Therefore, the above-mentioned architecture and control method can significantly reduce power consumption without introducing excessive noise into the generated clock signal.

In addition, the above-mentioned architecture and control method are relatively simple. Therefore, the complexity of implementing the concept of the present invention is also low. In addition, the above architecture and control method can be used in any communication system that requires low power consumption, high-order modulation, and / or fast and stable, such as 5G, LTE, WiFi, and so on.

Embodiments of the invention can be implemented in any way. For example, the above embodiments may be implemented by hardware, software, or a combination thereof. Any component or collection of components that perform the functions described above may generally be considered as one or more processors that can control the functions described above. One or more processors may be implemented in a variety of ways, such as through dedicated hardware, or general hardware implementation using microcode or software programming to perform the functions described above.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The above embodiments are only for illustration and not for limiting the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application. All equal changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (10)

A frequency generating circuit includes: a frequency synthesizer circuit, receiving a processed reference clock signal, and generating a radio frequency clock signal according to the processed reference clock signal; and a reference clock signal processor, from a The oscillator receives an initial reference clock signal and processes the initial reference clock signal according to an instruction signal to generate the processed reference clock signal, wherein the instruction signal is based on a required reference time of a communication device. Pulse frequency generation, and when the required reference clock frequency is higher than a first threshold, a frequency of the processed reference clock signal is a multiple of a frequency of the initial reference clock signal; when the When the required reference clock frequency is lower than a second threshold, the frequency of the initial reference clock signal is a multiple of the frequency of the processed reference clock signal. The frequency generating circuit according to item 1 of the patent application range, wherein when a signal-to-noise ratio required for the communication device to communicate with a network device is higher than a predefined signal-to-noise ratio threshold, the The reference clock frequency is higher than the first threshold; and when the required signal-to-noise ratio is not higher than the predefined signal-to-noise ratio threshold, the required reference clock frequency is lower than The second threshold. The frequency generating circuit according to item 1 of the scope of patent application, wherein when the required clock frequency stabilization time of a system of the communication device is shorter than a predefined stabilization time threshold, the required reference clock frequency is Higher than the first threshold; and when the required clock frequency stabilization time of the system is not shorter than the predefined stabilization time threshold, the required reference clock frequency is lower than the second threshold. The frequency generating circuit according to item 1 of the scope of patent application, wherein when the communication device does not need to save power, the required reference clock frequency is higher than the first threshold value; and when the communication device requires When saving power, the required reference clock frequency is lower than the second threshold. The frequency generation circuit according to item 1 of the scope of patent application, wherein the reference clock signal processor selectively outputs the rising / falling edge of the initial reference clock signal according to the instruction signal to generate the reference clock signal. Refer to the clock signal after processing. A communication device includes: a frequency generating circuit that generates a radio frequency clock signal based on an initial reference clock signal; and a reference clock controller that generates an instruction signal according to a required reference clock frequency, wherein the said The frequency generating circuit includes: a frequency synthesizer circuit that receives a processed reference clock signal and generates the radio frequency clock signal according to the processed reference clock signal; and a reference clock signal processor that oscillates from an oscillator The receiver receives the initial reference clock signal and processes the initial reference clock signal according to the instruction signal to generate the processed reference clock signal, wherein when the required reference clock frequency is higher than a first reference clock signal At a threshold, a frequency of the processed reference clock signal is a multiple of a frequency of the initial reference clock signal; when the required reference clock frequency is lower than a second threshold, the initial reference The frequency of the clock signal is a multiple of the frequency of the processed reference clock signal. The communication device according to item 6 of the scope of patent application, wherein when the reference clock controller determines that a signal-to-noise ratio required to communicate with a network device is higher than a predefined signal-to-noise ratio threshold, The required reference clock frequency is higher than the first threshold; and when the signal-to-noise ratio required for communication with the network device is not higher than the predefined signal-to-noise ratio threshold, all The required reference clock frequency is lower than the second threshold. The communication device according to item 6 of the scope of patent application, wherein when the reference clock controller determines that the required clock frequency stabilization time of a system is shorter than a predefined stabilization time threshold, the required reference clock The frequency is higher than the first threshold; and when the required clock frequency stabilization time of the system is not shorter than the predefined stabilization time threshold, the required reference clock frequency is lower than the second threshold . The communication device according to item 6 of the scope of patent application, wherein when the reference clock controller determines that power saving is not required, the required reference clock frequency is higher than the first threshold value; and When the power is on, the required reference clock frequency is lower than the second threshold. The communication device according to item 6 of the scope of patent application, wherein the reference clock signal processor selectively outputs a rising / falling edge of the initial reference clock signal according to the instruction signal to generate the processing. Post reference clock signal.